POS1008 FACTORS ASSOCIATED WITH HIP INVOLVEMENT AND ITS IMPACT ON TREATMENT DECISION IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS; TREASURE EXPERIENCE
Authors: E. Durak Ediboglu, U. Kalyoncu, D. Solmaz, T. Kaşifoğlu, E. Tekgoz, C. Bes, A. Erden, B. Yağiz, N. A. Kanitez, A. İ. Ertenli, B. N. Coşkun, R. Mercan, S. Kiraz, V. Yazisiz, O. Küçükşahin, A. Ateş, R. Yilmaz, Y. Pehlivan, H. Emmungil, N. S. Yasar Bilge, G. Kimyon, E. D. Ersözlü, E. Dalkiliç, S. S. Koca, S. Akar
Journal: Annals of the Rheumatic Diseases (2022)

Background Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease affecting sacroiliac joints, spine and peripheral joints. In addition to spinal and peripheral manifestations, root joints (hip or sholder) involvement may also develop. Hip involvement is reported 24-36% in patients with Ankylosing Spondylitis (AS) by clinical evaluation of the rheumatologists. However, there is limited data regarding the factors related with the presence of hip involvement and treatment preference in patients with axSpA. Objectives The aim of this study was to evaluate the factors/covariates associated with the hip involvement and its impact on the treatment preferences in patients with axSpA patients who initiated their first biologic therapy. Methods In total, 1600 axSpA patients who initiated his/her first biologic were included in the study. The data for the current study was obtained from the TReasure web-based registry. Baseline demographics and disease related characteristics were collected. Characteristics and treatment preference of patients with and without hip involvement were compared. The factors/covariates associated with the presence of hip involvement were evaluated by regression analysis. Results Hip involvement was reported in 375 patients (23.4%). Patients with hip involvement were more common male patients in addition they had lower education level, lower BMI and more frequent HLA-B27 positivity as well as longer disease duration. Hip involvement was more frequent in patients with r-axSpA than patients with nr-axSpA. We found lower percentages of peripheral arthritis, enthesitis and dactylitis, higher BASFI or ASDAS-CRP scores, higher serum CRP levels and ESR values in patients with hip involvement. Moreover, patients with hip involvement had less frequently SpA-related family history (Table 1). When we analyzed patients according to age at diagnosis (≥ 16 years, &lt;16 years) we found that patients with hip involvement were more common in juvenile onset axSpA group. In multivariate analysis, we found that lower education level (OR:2.029, 95%CI:[1.461-2.817]; p&lt;0.001), diagnosis (r-axSpA) (OR:0.532, 95%CI:[0.337-0.839]; p=0.007) longer disease duration (OR:1.002, 95%CI:[1.001-1.004]; p=0.002), lower percentages of enthesitis (OR:0.405, 95%CI:[0.283-0.579]; p&lt;0.001), higher BASFI scores (OR:1.086, 95%CI:[1.025-1.151]; p=0.005) and serum CRP levels (OR:1.005, 95%CI:[1.001-1.010]; p=0.019) absence of SpA family history (OR:0.713, 95%CI:[0.528]; p=0.027) were associated with hip involvement. Table 1. Characteristics of patients with axSpA All patients (n=1600) Hip involvement (+) (n=375) Hip involvement (-) (n=1225) P* Juvenile (&lt;16 years) onset, n(%) 30 (1.9) 12 (3.2) 18 (1.5) 0.031 Male sex, n(%) 940 (58.8) 255 (68) 685 (55.9) &lt;0.001 HLA-B27 positivity, n(%) 605 (55) 178 (62.7) 427 (52.3) 0.002 BMI, kg/m 2 mean (SD) 27.2 (5.2) 26.7 (5.0) 27.4 (5.2) 0.023 Education duration (≤12 years), n (%) 1014 (65.9) 263 (71.3) 751 (64.2) 0.013 mNY positivity, n(%) 1276 (79.8) 338 (90.1) 938 (76.6) &lt;0.001 Disease duration (month) median (IQR 25-75) 82 (36-151) 111 (52-200) 74.5 (32-139) &lt;0.001 SPA-related family history, n (%) 544 (34) 110 (29.3) 434 (35.4) 0.029 BASFI, mean (SD) 3.9 (2.5) 4.3 (2.1) 3.8 (2.7) 0.007 ASDAS-CRP, mean (SD) 3.1 (1.5) 3.7 (1.4) 2.9 (1.5) &lt;0.001 CRP (mg/dl), median (IQR 25-75) 8.6 (3-21) 12.0 (4.0-27.9) 7.6 (2.5-19) &lt;0.001 When we compared the treatment patterns of axSpA patients with and without hip involvement, we found that the percentages of NSAID as well as csDMARD use were similar in groups. However, the percentages of patients who were prescribed etanercept were higher in axSpA patients with hip involvement (p&lt;0.001). Conclusion In addition to inflammation and function, hip involvement seems to be related with diagnosis (r-axSpA), education level and absence of SpA family history. Moreover, enthesitis may not accompany hip involvement. Disclosure of Interests None declared